Disabled Fast Startup. Restarted. Ran scan. MB scan still hangs at Heuristic Analysis i.e. no change in behavior. Still unable to manually terminate scan. Have to restart to end scan cycle. Will attempt to do run procdump sometime today. Last attempt failed. The program said a file was sent to my desktop, but did not appear.
I'm assuming all protection layers in MB are functioning normally. The Dashboard says everything is turned on. BTW, the Dashboard says last scan completed.

Here's a new wrinkle. I just did a manual scan and Malwarebytes hung during the Heuristics Analysis (it got through the File Scan System OK). Attempted to cancel the scan unsuccessfully after 10 minutes ( pressed cancel button but then the scan continued and cancel button greyed out). Quit Malwarebytes and attempted to restart program, but Malwarebytes error message: Unable to start. Unable to connect the Service. Unfortunately I haven't installed the log program yet. Will have to restart the computer.

I am having a similar problem. I have a daily scheduled Threat Scan that has been working perfectly a couple of years until a few days ago. Threat Scans usually complete in about five minutes. However when I checked it this morning, the Scan File System (wheel turning) had been running for 85 hours (I normally don't check Malwarebytes to see if scheduled scans complete) I couldn't manually cancel the scan (option greyed out). I quit Malwarebytes, but couldn't restart the program (Windows error message - Malwarebytes can't be restarted). Had to reboot to get Malwarebytes running again. After the reboot I completed two successful manual Threat Scans, but the scheduled scan hangs at around 214,500 items scanned.